Submission #628707

#	Time	Username	Problem	Language	Result	Execution time	Memory
628707		evenvalue	Meetings (IOI18_meetings)	C++17	17 / 100	118 ms	8620 KiB

meetings

#include "meetings.h"
#include <bits/stdc++.h>
using namespace std;

template<typename T>
using min_heap = priority_queue<T, vector<T>, greater<T>>;
template<typename T>
using max_heap = priority_queue<T, vector<T>, less<T>>;

using int64 = long long;
using ld = long double;

constexpr int kInf = 1e9 + 10;
constexpr int64 kInf64 = 1e15 + 10;
constexpr int kMod = 1e9 + 7;

template<class node, class F = std::function<node(const node &, const node &)>>
class SegTree {
  int n = 0;
  std::vector<node> t;
  F unite;

  void build(const int x, const int l, const int r, const std::vector<node> &a) {
    if (l == r) {
      t[x] = a[l];
      return;
    }
    const int mid = (l + r) / 2;
    const int y = 2 * (mid - l + 1) + x;
    build(x + 1, l, mid, a);
    build(y, mid + 1, r, a);
    t[x] = unite(t[x + 1], t[y]);
  }

  void update(const int x, const int l, const int r, const int p, const node &v) {
    if (l == p and p == r) {
      t[x] = v;
      return;
    }
    const int mid = (l + r) / 2;
    const int y = 2 * (mid - l + 1) + x;
    if (p <= mid) {
      update(x + 1, l, mid, p, v);
    } else {
      update(y, mid + 1, r, p, v);
    }
    t[x] = unite(t[x + 1], t[y]);
  }

  node query(const int x, const int l, const int r, const int ql, const int qr) const {
    if (ql <= l and r <= qr) {
      return t[x];
    }
    const int mid = (l + r) / 2;
    const int y = 2 * (mid - l + 1) + x;
    if (qr <= mid) {
      return query(x + 1, l, mid, ql, qr);
    } else if (mid < ql) {
      return query(y, mid + 1, r, ql, qr);
    } else {
      return unite(query(x + 1, l, mid, ql, qr), query(y, mid + 1, r, ql, qr));
    }
  }

public:
  SegTree() = default;
  explicit SegTree(const int n, const node e, F f) : n(n), t(2 * n - 1, e), unite(std::move(f)) {}
  explicit SegTree(const std::vector<node> &a, F f) : n(a.size()), t(2 * (a.size()) - 1), unite(std::move(f)) {
    build(0, 0, n - 1, a);
  }

  void set(const int p, const node &v) {
    assert(0 <= p and p < n);
    update(0, 0, n - 1, p, v);
  }

  [[nodiscard]] node get(const int l, const int r) const {
    assert(0 <= l and l <= r and r < n);
    return query(0, 0, n - 1, l, r);
  }
};

struct node {
  int length = -1;
  int streak = -1;
  int prefix = -1;
  int suffix = -1;
};

std::vector<long long> minimum_costs(std::vector<int> H, std::vector<int> L, std::vector<int> R) {
  const int n = H.size(), q = L.size();

  SegTree<node> st(n, node(), [](const node &l, const node &r) {
    node ret;
    ret.length = l.length + r.length;
    ret.streak = max({l.streak, r.streak, l.suffix + r.prefix});
    ret.prefix = (l.length == l.streak ? l.streak + r.prefix : l.prefix);
    ret.suffix = (r.length == r.streak ? l.suffix + r.streak : r.suffix);
    return ret;
  });

  for (int i = 0; i < n; i++) {
    if (H[i] == 1) {
      st.set(i, node({1, 1, 1, 1}));
    } else {
      st.set(i, node({1, 0, 0, 0}));
    }
  }

  vector<int64> ans(q);
  for (int i = 0; i < q; i++) {
    const int streak = st.get(L[i], R[i]).streak;
    const int length = R[i] - L[i] + 1;
    ans[i] = 2 * length - streak;
  }
  return ans;
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 15
• Subtask 3: 17 / 17
• Subtask 4: 0 / 24
• Subtask 5: 0 / 40